Denver Mountain Parks and another smaller website on Denver Mountain Parks.
Chief Hosa Braille Nature Trail is within Denver’s Genesee Park. Take I-70 west to exit 153 “Chief Hosa”. At the off-ramp stop sign, turn north, then turn right on to a dirt road -Stapleton Drive. Follow Stapleton Drive about 1 mile to the trailhead for the Braille Nature Trail. The trail has a vinyl-coated cable for guiding visually-impaired people. Metal interpretive signs along the trail in Braille and printed words explain the surrounding ecology. The signs are great, but some scumbag(s) have shot up some of them. The trail is about a third of a mile through forest and is not wheelchair accessible.
The alpine trail between Summit Lake and the Chicago Lakes Overlook has just recently been redone to be wheelchair accessible. Summit Lake is about 12,800′ above sea level. The air is thin, temperatures are likely to be chilly, and it can snow anytime of year. It is also beautiful! GPS at parking lot: N39° 35.904 W105° 38.430.
Echo Lake is another Denver Mountain Park. GPS for eastern (uphill) end: N39° 39.382 W105° 35.820. GPS for western (downhill) end: N39° 39.617 W105° 36.281. Although not signed as wheelchair accessible, the short trail between the Lodge and Echo Lake is a gentle downhill trip on crusher fines that takes you through the englemann spruce forest to the lake. There is parking at both ends of the trail, so someone could be dropped off at the top and join their group at the lake. It is not a loop trail.